The invention relates to a bow formation for folding tops which can be pushed together on vehicle bodies or containers having rigid or flexible end walls and side walls and upper longitudinal flanges which limit the height of the body upwards and are formed by profiled rails, wherein a tarpaulin which fits over the roof region of the body is supported by bows which are arranged at predetermined, uniform spacings from one another and span the width of the loading surface, said bows being supported on the longitudinal flanges of the body and supported at their two ends both in the horizontal and vertical directions in each case by means of a roller carriage which at least partially grips around the longitudinal flanges or by means of a corresponding roller arrangement, and are guided in a longitudinally displaceable manner on complimentarily designed guide tracks of the upper longitudinal flanges of the body.
Tarpaulin roofs are known in practice in which the roof tarpaulin is supported by bows which are not connected in an immovable manner to the frame of the vehicle body. The bows are basically used whenever at least occasional loading of the vehicle or container from above is required. In the case of the simplest known design of a tarpaulin roof of the abovementioned generic type for vehicle bodies or containers, the bows supporting the roof tarpaulin are connected to the upper longitudinal flanges of the vehicle body or of the container in such a manner that they can only be detached from the longitudinal flanges by being removed, and the tarpaulin has to be rolled up for the purpose of opening the tarpaulin roof. In such a form of design for a tarpaulin roof the bows can indeed be designed in a very simple manner, but the opening of the roof necessitates a considerable expenditure of energy and effort.
In the case of another design, which is known in practice, of tarpaulin roofs for vehicle bodies or containers, provision is made for the bows which support the roof tarpaulin to be supported at both ends via rollers or the like in a longitudinally moveable manner in guide-rail-like profiled forms of the upper longitudinal flanges of the frame of a vehicle body. Although tarpaulin roofs of this type are distinguished in that opening of the roof can be brought about relatively easily by pushing together the tarpaulin and bows, they are, on the other hand, affected by the disadvantage of a considerable outlay on production for the equipping of the bows with suitable rollers. This is true in particular if the roller arrangement in conjunction with the use of a commercially available profile material for the design of the upper longitudinal flanges of a vehicle body or of a container has to be designed in the form of a roller carriage, as is the case with most of the sliding folding tops which are currently customary.
One design, which is known in practice, of bows which are provided at both ends with a roller carriage for supporting and guiding in profiled rails makes provision for the bow to consist of a bow shaft, which is formed by a length section of a continuous hollow profile material, and of roller carriages connected to the said bow shaft at both ends, the roller carriages being prefabricated as independent units and being connected to the bow shaft. Although a design of this type involves the bows being less expensive, because of the possibility for decentralized production of the roller carriages and the simplicity of the connection thereof to the bow shaft, it is still affected by the outlay for assembling the bow which consists of a plurality of parts.
It is an object of the invention to provide a bow formation for tarpaulin folding tops or tarpaulin roofs of vehicle bodies or containers, which permits bows of any desired shape or size to be realized together with the required bearings for supporting and guide rollers, in particular roller carriages, as single-piece components at a very low outlay, and in which, moreover, sufficient strength is also ensured for the regions of a bow which form the roller carriages.
In the case of the bow formation mentioned at the beginning, this object may be achieved in that the bow shaft is designed as a single piece together with the roller carriages which guide and support it at both ends on the guide tracks of the upper longitudinal flanges of the body.
A bow formation of this type opens up the possibility of forming a bow in its entirety, i.e. together with a bow shaft and roller bearings, in particular roller carriages, from a simple hollow profile section and therefore of avoiding the conventionally required constructional outlay for assembling the bow.
A particularly suitable method of realizing bows which are designed as a single piece together with their bearings on the upper longitudinal flanges of the vehicle body resides in the fact that the bows consist of length sections of a hollow profile material of any desired profile cross section, the roller carriages which are arranged at the two ends of the said bows being formed by non-cutting deformation of the hollow profile material.
In a particularly preferred construction, provision is made for the hollow profile material in particular forming the shaft part of a bow to have a square or rectangular profile cross section and to be compressed in both end regions of a bow to form a double-layered flat material cross section and, in order to form a roller carriage, to be angled at least approximately perpendicularly with respect to the profile axis of the hollow profile material.
Excellent stability is achieved by the end regions of the bows, which end regions form roller carriages, compressed to form double-layered flat material cross sections and angled perpendicularly with respect to the profile axis of the hollow profile material, by the fact that the two wall regions of the hollow profile material which rest on each other in the region of each end, compressed to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow are connected non-detachably to each other, preferably via means reaching through them, in particular rivet bolts. In order to obtain the desired stability, provision may also be made in accordance with the invention for the wall regions, which rest on each other, of the hollow profile material to be connected to one another non-detachably and non-displaceably relative to one another by the application of welding points or using another suitable joining method, but in the interests of the least possible outlay on production, provision is preferably made for the rivet bolts, which reach through the two wall regions, resting on each other, of each of the ends, compressed to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow to be formed by the rivet bolts which are in any case required for connection of the bearings for the running or guide rollers of a roller carriage.
In a further refinement of the bow formation according to the invention, in order to increase the stability of the end regions of the bows forming the roller carriages, provision may furthermore be made for the angled portion of the end, compressed to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow to include a bulge which is orientated as an extension of the longitudinal extent of the bow, and the double-layered flat material cross section to be provided in the region of its angled portion with an inwardly directed reinforcing bead.
Specifically, then, with a respective adaptation to the other characteristics of the folding top for which the bow is intended in each case, provision may further be made for the ends, compressed in each case to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow to be provided with two running rollers rotating about axes orientated in an axially parallel manner to the bow shaft and with at least one guide roller rotating about an axis orientated perpendicularly with respect to the axis of the bow shaft.
In a further adaptation of the bow formation to particular formations of the folding top for which the respective bow is intended, provision may furthermore also be made for the ends, compressed in each case to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow to form, as an extension of the bow surface, a fastening plane for bearing elements for a tarpaulin, which bearing elements connect adjacent bows to one another, the bearing elements consisting of a semi-rigid material, in particular of a plastic material reinforced locally, and being connected to the end regions of the bow by means of rivet bolts.
In this case, according to a further feature, the bow formation according to the invention is not exclusively limited to the provision of the bow with roller arrangements or roller carriages, but may likewise also be used with equally great advantage in conjunction with other forms of designing the bow support on the upper longitudinal flanges of a folding-top frame, in particular by the fact that the ends, compressed to form a double-layered flat material cross section, of a hollow-profile-material section forming a bow each form a bearing for a pair of struts supporting the bow against the guide tracks of the upper longitudinal flanges of the body.
Further advantages and features of the invention emerge from the following description and from the subclaims.